You hurl a small piece of fire at a target.

If it hits the target explodes.(only part of the target explodes if it is bigger than 1 cubic ft)

If this is directed at a living creature the must make a dc 20 con check. On a failure the target takes 10d6 fire damage. On a success nothing happens

if the spell succeeds any creature within 10ft must succeed on a dc 15 dex saving throw or take 8d6 fire damage. On a success they take half damage

If the spell succeeds any creature within 20 ft must succeed on a dc 10 dex saving throw or take 4d6 fire damage. On a success they take no damage.